Both group A and group C vaccines have documented short-term efficacy levels of 85–100% in older children and adults. However, group C vaccines do not prevent disease in children under 2 years of age, and the efficacy of group A vaccine in children under 1 year of age is unclear. Group Y and W-135 polysaccharides have been shown to be immunogenic only in children over 2 years of age.

A protective antibody response occurs within 10 days of vaccination. In schoolchildren and adults, the bivalent and tetravalent polysaccharide vaccines appear to provide protection for at least 3 years, but in children under 4 years the levels of specific antibodies decline rapidly after 2–3 years.

The currently available bivalent and tetravalent meningococcal vaccines are recommended for immunization of specific risk groups as well as for large-scale immunization, as appropriate, for the control of meningococcal outbreaks caused by vaccine-preventable serogroups (A and C, or A, C, Y, W-135 respectively). Travellers who have access to the tetravalent polysaccharide vaccine (A, C, Y, W-135) should opt for this rather than the bivalent vaccine because of the additional protection against groups Y and W-135.

These vaccines do not provide any protection against other serogroups such as group B and group X meningococci, which are important causes of meningococcal disease in some countries.

Precautions and contraindications — polysaccharide vaccine

The internationally available polysaccharide vaccines are safe, and significant systemic reactions have been extremely rare. The most common adverse reactions are erythema and slight pain at the site of injection for 1–2 days. Fever exceeding 38.5 °C occurs in up to 2% of vaccinees. No significant change in safety or reactogenicity has been observed when the different group-specific polysaccharides are combined into bivalent or tetravalent meningococcal vaccines.

Duration of protection: For 1 and 2: 3–5 years or more; for 3: not known

Contraindications: Serious adverse reaction to previous dose

Adverse reactions: Occasional mild local reactions; rarely, fever

Before departure: 2 weeks

Consider for: 1 and 2: all travellers to countries in the sub-Saharan meningitis belt and to areas with current epidemics; Hajj and Umrah pilgrims (required); 3: a cheaper alterative to 1 and 2 for travellers to highly endemic African countries

Special precautions: Children under 2 years of age are not protected by the vaccine